pcapngWriter

PCAPNG file writer of protocol packets

Since R2020b

Description

The pcapngWriter object writes generated and recovered protocol packets to a packet capture next generation (PCAPNG) file (.pcapng).

You can write these packet types to a PCAPNG file:

• Generated and recovered Bluetooth low energy (LE) link layer (LL) packets (requires Bluetooth^® Toolbox)

• Generated and recovered 5G NR protocol packets (requires 5G Toolbox™)

• Generated and recovered WLAN protocol packets (requires WLAN Toolbox™)

Creation

Syntax

pcapngObj = pcapngWriter

pcapngObj = pcapngWriter(Name,Value)

Description

pcapngObj = pcapngWriter creates a default PCAPNG file writer object.

pcapngObj = pcapngWriter(Name,Value) sets properties using one or more name-value pair arguments. Enclose each property name in quotes. For example, 'ByteOrder','big-endian' specifies the byte order as big-endian.

Properties

Note

The pcapngWriter object does not overwrite the existing PCAPNG file. Each time when you create this object, specify a unique PCAPNG file name.

FileName — Name of the PCAPNG file

'capture' (default) | character row vector | string scalar

Name of the PCAPNG file, specified as a character row vector or a string scalar.

Data Types: char | string

ByteOrder — Byte order

'little-endian' (default) | 'big-endian'

Byte order, specified as 'little-endian' or 'big-endian'.

Data Types: char | string

FileComment — Comment for PCAPNG file

'' (default) | character vector | string scalar

Comment for the PCAPNG file, specified as a character vector or a string scalar.

Data Types: char | string

Object Functions

Specific to This Object

write	Write protocol packet data to PCAP or PCAPNG file
writeCustomBlock	Write custom block to PCAPNG file
writeInterfaceDescriptionBlock	Write interface description block to PCAPNG file

Examples

Write Bluetooth LE Link Layer Packet to PCAPNG File

Create a PCAPNG file writer object, specifying the name of the PCAPNG file. Specify the Bluetooth LE link type.

pcapngObj = pcapngWriter('FileName','BLELLCapture');

Write an interface description block for Bluetooth LE.

interfaceName = 'Bluetooth LE interface';
bleLinkType = 251;
interfaceId = writeInterfaceDescriptionBlock(pcapngObj,bleLinkType, ...
    interfaceName);

Specify a Bluetooth LE LL packet.

llpacket = '42BC13E206120E00050014010A001F0040001700170000007D47C0';

Write the Bluetooth LE LL packet to the PCAPNG format file.

timestamp = 0;                                 % Packet arrival time in POSIX® microseconds elapsed since 1/1/1970
packetComment = 'This is a Bluetooth LE packet';
write(pcapngObj,llpacket,timestamp,interfaceId,'PacketComment', ...
    packetComment);

References

[1] Tuexen, M. “PCAP Next Generation (Pcapng) Capture File Format.” 2020. https://www.ietf.org/.

[2] Group, The Tcpdump. “Tcpdump/Libpcap Public Repository.” Accessed May 20, 2020. https://www.tcpdump.org.

[3] “Development/LibpcapFileFormat - The Wireshark Wiki.” Accessed May 20, 2020. https://www.wireshark.org.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2020b